To calculate the mass of 5.0 moles of nitrogen atoms, we need to know the molar mass of nitrogen, which is 14.01 grams per mole. This means that 1 mole of nitrogen atoms has a mass of 14.01 grams.

Therefore, the mass of 5.0 moles of nitrogen atoms can be calculated as follows:

Mass = moles × molar mass

Mass = 5.0 moles × 14.01 grams per mole

Mass = 70.05 grams

Hence, the mass of 5.0 moles of nitrogen atoms is 70.05 grams.